﻿<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS3实现黑色卷角翻页导航条</title>
    <style type="text/css">
        ul, li {
            list-style-type: none;
            padding: 0;
        }

        .form {
            width: 408px;
            height: 200px;
            background: #2f2f2f;
            position: relative;
            overflow: hidden;
            margin: 30px auto;
        }

        .corner {
            background: -webkit-linear-gradient(45deg, #2e2e2e 24%, #5F5F5F 40%, #6f6f6f 43%, #5F5F5F 46%, #2F2F2F 50%, #fff 50%, #fff);
            background: -moz-linear-gradient(45deg, #2e2e2e 24%, #5F5F5F 40%, #6f6f6f 43%, #5F5F5F 46%, #2F2F2F 50%, #fff 50%, #fff);
            height: 90px;
            background: -o-linear-gradient(45deg, #2e2e2e 24%, #5F5F5F 40%, #6f6f6f 43%, #5F5F5F 46%, #2F2F2F 50%, #fff 50%, #fff);
            height: 90px;
            background: -ms-linear-gradient(45deg, #2e2e2e 24%, #5F5F5F 40%, #6f6f6f 43%, #5F5F5F 46%, #2F2F2F 50%, #fff 50%, #fff);
            height: 90px;
            background: linear-gradient(45deg, #2e2e2e 24%, #5F5F5F 40%, #6f6f6f 43%, #5F5F5F 46%, #2F2F2F 50%, #fff 50%, #fff);
            height: 90px;
            width: 90px;
            height: 90px;
            border-radius: 0 0 0px 90px / 0 0 0 30px;
            -webkit-transform: rotate(-90deg);
            -moz-transform: rotate(-90deg);
            -o-transform: rotate(-90deg);
            -ms-transform: rotate(-90deg);
            transform: rotate(-90deg);
            position: absolute;
            left: -4px;
            top: -4px;
            box-shadow: 5px 2px 8px black;
            overflow: hidden;
            -webkit-transition: all 0.3s linear 0s;
            -moz-transition: all 0.3s linear 0s;
            -o-transition: all 0.3s linear 0s;
            -ms-transition: all 0.3s linear 0s;
            transition: all 0.3s linear 0s;
        }

        .corner:after {
            height: 100%;
            width: 100%;
            position: absolute;
            content: "";
            top: -15px;
            left: -82px;
            border-radius: 90px 90px 0px 0 / 40px 40px 0 0;
            z-index: 1;
            background: #2F2F2F;
            -webkit-transform: rotate(77deg);
            -moz-transform: rotate(77deg);
            -o-transform: rotate(77deg);
            -ms-transform: rotate(77deg);
            transform: rotate(77deg);
            box-shadow: 0px 0px 8px black inset;
        }

        .button {
            float: left;
            height: 40px;
            margin: 20px 20px;
            border-radius: 30px;
            border: 1px solid #151515;
            box-shadow: 0px 2px 2px rgba(0, 0, 0, 0.6);
            overflow: hidden;
        }

        .button li {
            float: left;
        }

        .button li a {
            float: left;
            display: block;
            text-decoration: none;
            padding: 0 20px;
            height: 40px;
            line-height: 36px;
            font-size: 14px;
            color: #eee;
            text-align: center;
            border-right: 1px solid #151515;
            box-shadow: -1px 0px 0px rgba(255, 255, 255, 0.1) inset, inset 0px -1px 1px rgba(200, 200, 200, 0.1), inset 0px 1px 2px rgba(255, 255, 255, 0.1);
            text-shadow: 0px -1px 0px #000;
            background: -webkit-linear-gradient(top, rgba(200, 200, 200, 0.1) 0%, rgba(200, 200, 200, 0.1) 50%, #222 50%, #222);
            background: -moz-linear-gradient(top, rgba(200, 200, 200, 0.1) 0%, rgba(200, 200, 200, 0.1) 50%, #222 50%, #222);
            background: -o-linear-gradient(top, rgba(200, 200, 200, 0.1) 0%, rgba(200, 200, 200, 0.1) 50%, #222 50%, #222);
            background: -ms-linear-gradient(top, rgba(200, 200, 200, 0.1) 0%, rgba(200, 200, 200, 0.1) 50%, #222 50%, #222);
            background: linear-gradient(top, rgba(200, 200, 200, 0.1) 0%, rgba(200, 200, 200, 0.1) 50%, #222 50%, #222);
        }

        .button li:first-child a {
            border-radius: 30px 0 0 30px;
        }

        .button li:last-child a {
            border-radius: 0px 30px 30px 0;
            border-right: none;
        }

        .button li a:hover {
            cursor: pointer;
            background: -webkit-linear-gradient(top, rgba(50, 50, 50, 0.4) 20%, rgba(100, 100, 100, 0.3));
            background: -moz-linear-gradient(top, rgba(50, 50, 50, 0.4) 20%, rgba(100, 100, 100, 0.3));
            background: -o-linear-gradient(top, rgba(50, 50, 50, 0.4) 20%, rgba(100, 100, 100, 0.3));
            background: -ms-linear-gradient(top, rgba(50, 50, 50, 0.4) 20%, rgba(100, 100, 100, 0.3));
            background: linear-gradient(top, rgba(50, 50, 50, 0.4) 20%, rgba(100, 100, 100, 0.3));
            box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.8) inset;
            color: #b7def5;
            text-shadow: 0px 0px 8px rgba(0, 162, 255, 0.8);
        }

        .notice {
            position: relative;
            padding: 10px 0 0 25px;
            margin: 20px auto;
            width: 120px;
        }

        .arrow {
            width: 13px;
            height: 20px;
            background: #FC9;
            position: absolute;
            top: 0px;
            left: 0px;
            -webkit-animation: notices linear 0.8s infinite;
            -moz-animation: notices linear 0.8s infinite;
            -o-animation: notices linear 0.8s infinite;
            -ms-animation: notices linear 0.8s infinite;
            animation: notices linear 0.8s infinite;
        }

        .arrow:after {
            width: 0;
            height: 0;
            border-width: 12px;
            border-style: solid dashed dashed dashed;
            border-color: #FC9 transparent transparent transparent;
            position: absolute;
            bottom: -22px;
            left: -5px;
            display: block;
            content: "";
        }

        @-webkit-keyframes notices {
            0% {
                top: 0px;
            }
            50% {
                top: 10px;
            }
            100% {
                top: 0px;
            }
        }

        @-moz-keyframes notices {
            0% {
                top: 0px;
            }
            50% {
                top: 10px;
            }
            100% {
                top: 0px;
            }
        }

        @-o-keyframes notices {
            0% {
                top: 0px;
            }
            50% {
                top: 10px;
            }
            100% {
                top: 0px;
            }
        }

        @-ms-keyframes notices {
            0% {
                top: 0px;
            }
            50% {
                top: 10px;
            }
            100% {
                top: 0px;
            }
        }

        @keyframes notices {
            0% {
                top: 0px;
            }
            50% {
                top: 10px;
            }
            100% {
                top: 0px;
            }
        }
    </style>
</head>
<body>
<div class="notice">
    <div class="arrow"></div>
    拖动书角看看 *^_^*
</div>

<div class="form" id="form">
    <div class="corner" id="corner"></div>
    <ul class="button">
        <li><a href="">Welcome</a></li>
        <li><a href="">Blog</a></li>
        <li class="navcurrent"><a href="">About Us</a></li>
        <li class="borderno"><a href="">站长素材</a></li>
    </ul>

</div>

<script type="text/javascript">
    (function () {
        let form = document.getElementById("form");
        let corner = document.getElementById("corner")
        let ftop = form.offsetTop;
        let fleft = form.offsetLeft;
        let switchopen = 0;
        corner.onmousedown = function (e) {
            e.preventDefault();
            form.style.cursor = "move";
            switchopen = 1;
        }
        form.onmousemove = function (e) {
            if (switchopen === 1) {
                if (e.pageX - fleft > 90 || e.pageY - ftop > 90) {
                    corner.style.width = corner.style.height = 90 + "px";
                    corner.style.left = corner.style.top = -4 + "px"
                } else {
                    corner.style.width = corner.style.height = e.pageY - ftop + "px";
                }
            }
        }
        form.onmouseup = function () {
            switchopen = 0;
            this.style.cursor = "default";
        }
    })()
</script>
</body>
</html>